I'm going to have to add a damper to my stovepipe in the off season. Have an adjustable ultrablack pipe, which I believe is 36 inches sliding inside 36 inches. Same pipe that I used for my Fireview, rear flue, now recommissioned for my Progress Hybrid top vent. With the top vent, I only have a little over 14 inches of pipe below the sliding joint. Have a probe thermometer mounted just below the joint. The pipe section with damper I believe is 4 inches in exerior (exposed) length. Where does it get installed in relation to stove/adjustable pipe?